Device for locking a rotatable element in different positions of rotation thereof



H. D. BAXTER, JR

March '4, 1958 DEVICE FOR LOCKING A ROTATABLE ELEMENT IN DIFFERENT POSITIONS OF ROTATION THEREOF Filed 001'" 18, 1954 lI-LF i -Ba X. 56 7", Jr,

5 )7. ATTORNEY 9 M H6. rd M Z 2 5, F 8 N I 4/ .w m v 2 0 L March 1958 H. D. BAXTER, JR 2,325,426

nEvTcE FOR LOCKING A ROTATABLE ELEMENT IN DIFFERENT E POSITIONS OF ROTATION THEREOF Filed Oct. 18, 1954 2 Sheets-Sheet 2 {i 3 INVENTOR Q '7}7 5 I? 7 mflaxfe 7,157

ATTORNEY rune DEVICE FOR LOCKING A ROTATABLE ELEMENT m DIFFERENT POSITIONS F RGTATION THEREOF Homer D. Baxter, Jr., Charleston, W. Va.

Application October 18, 1954, Serial No. 462,781

2 Claims. (Cl. 188-69) This invention relates to a novel drafting table including a rotatable center section capable of being revolved relative to an outer stationary section of the table and which may be held in any rotatably adjusted position for most efficient use.

More particularly, it is an aim of the present invention to provide a drafting table which will eliminate the need of angles and through the use of which in conjunction with a conventional T-square any desired angle may be accurately drawn.

Another object of the invention is to provide a drafting table of maximum versatility and which especially adapts itself to efiicient use by a commercial artist in executing lettering on an are or in perspective.

A further object of the invention is to provide a drafting table by means of which the sheet may be turned with the rotatable section without moving the sheet relative thereto to obtain the most advantageous working position for the draftsman or artist and with the assurance that the sheet may be accurately returned to its original position.

Still a further object of the invention is to provide a drafting table having means whereby the rotatable section thereof may be held securely in each of 360 different positions of rotation to thereby enable work to be performed with a maximum of accuracy.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating a presently preferred embodiment thereof, and wherein:

Figure l is a top plan view of the drafting table;

Figure 2 is an enlarged top plan view, partly broken away of the drafting table, to illustrate the mechanism disposed beneath the table top in top plan;

Figure 3 is a front elevational view, partly broken away of the drafting table;

Figure 4 is an enlarged fragmentary detail sectional view, taken substantially along a plane as indicated by the line 4-4 of Figure 2;

Figure 5 is an enlarged fragmentary detail vertical sectional view taken substantially along a plane as indicated by the lines 5-5 of Figures 2 and 3;

Figure 6 is a fragmentary vertical sectional view taken substantially along a plane as indicated by the line 66 of Figure 5;

Figure 7 is an enlarged fragmentary vertical sectional view,'taken substantially along a plane as indicated 'by the line 77 of Figure 2, and

Figure 8 is a detail view partly in end elevation and partly in section of a portion of the apparatus.

Referring more specifically to the drawings, the improved drafting table in its entirety and comprising the invention is designated generally it} and includes a table top, designated generally 11, which is preferably substantially rectangular in shape. The table top 11 is'composed of an inner section 12 and an outer or marginal section 13. The section 12 is circular or disk shaped and United States Patent constitutes a cutout central portion of the outer section 13 and is mounted for rotation in a circular opening 14 of the table top section 13, formed by the cutting out of said central table top section 12. The table top section 12 thus constitutes a turntable. The table top 11 may be supported in an elevated position in any suitable manner as by means of depending legs 15 which are secured to depend from the corners of the outer section 13.

A spider shaped supporting bracket, designated generally 16, is disposed beneath the table top 11 and includs a central portion 17, a plurality of arms 18 and 180, which radiate from said portion 17 and plate portions 19 which constitute upwardly offset terminals of the arms 18 and 18a and which are disposed in a plane parallel to the plane of the central portion 17. The bracket 16 preferably includes four arms 18 and 18a which, as seen in Figure 2, are preferably not spaced equal distances apart so that each of the arms 18 and 13a forms an obtuse angle with the arm on one side thereof and an acute angle with the arm on the opposite side thereof, as illustrated in Figure 2. The plate portions 19 bear against the underside of the outer section 13, outwardly with respect to its opening 14- and are secured thereto by suitable headed fastenings 24} which extend upwardly therethrough and are secured in said outer section 13.

One longitudinal edge of the table top 11, as for example the bottom edge 21 thereof, as seen in Figures 1 and 2, constitutes the front edge of said table top. The two arms 18 are disposed nearer said front edge 21 than the arms 18:: and at substantially corresponding angles thereto. The arms 18 form'an obtuse angle with one another, as seen in Figure 2. Said arms 18 dilfer from the arms 18a only in that the arms 18 are provided with upwardly offset upwardly facing step portions or surfaces 22 adjacent their outer ends and which are disposed above the level of the upper surfaces of the inner portions of the arms 18 and substantially below the level of the upper surfaces of the plate portions 19. Each of the arms 18 and 18a includes an upwardly extending portion 23, on the upper ends of which the plate portions 19 are formed. A spindle 24 is anchored in each arm portion 25, near its upper end, and has a part extending inwardly therefrom on which a roller 25 is journalled. A spacing sleeve 26 is preferably mounted on each spindle 24 between the roller 25 and the adjacent arm portion 23. The rollers 25 are disposed beneath portions of the turn table 12 and are disposed to partially support said turn table for free rotation in the opening 14.

The central portion of the underside of the turntable.

l2 rests flush against the upper side of a disk or plate 27 which is secured to the turntable 12 by suitable headed fastenings 28 which extend upwardly therethrough and into the turntable 12 but which do not project through the upper surface of said turntable. The disk or plate 27 is provided with a centrally disposed depending boss 29 having a central bore extending upwardly into the plate 27 to form a socket 30, as best seen in Figure 7. The upper end of a shaft 31 is seated in the socket 30 and is secured therein by a setscrew 32 which is threaded radially throughthe boss into the socket 30. The shaft 31 extends downwardly from the boss 29 through the central hub portion 33 of a wheel 34. The wheel 34 is of relatively large diameter and the periphery thereof has teeth 35 extending completely therearound; In the embodiment of the invention as disclosed, the periphery of the wheel 34 is provided with 18.0 teeth 35. As seen in Figure 7, a setscrew 36 is threaded radially into a lower portion of the wheel hub 33 and against the shaft 31 tov secure the wheel to said shaft. The central portion 17 of the supporting bracket 16 is provided with a centrally disposed upwardly opening socket 37 in which is seated. the lower end or" a thrust bearing 3%, into which the has satisfis? the stars 31 extends. The hub 33 is provided with a downwardly opening recess or socket" g 39 in its lower'portion which fits over the upper part of the thrustbearing 38; rThus, the thrust bearing 38 provides an antifriction'support for the shaft 31, wheel 34,; iplate 27 and turntable 12, which arefmounted on and fixed to-s aid shaft f However, as previously stated, the V turntable 12 'is in part supported adjacent its periphery by the fouri rollers f Ajpair of corresponding levers 40 and-40a have bearing portions 41 spaced from'the ends thereof and which are disposedover the steps'22 of the bracket arms 18. As best seen in Figure 4, headed pins 42lexte'nddownwardly through said bearing portions 41 and-have threaded lowerends 43'whijch are anchored inithe st epjportiqns 22 andunthr'eaded upper stern portions 44 on whichthe r 'bearingportions 41 are journalled; A washer 45 may be positioned between each step '22 and'the bearing portion-41 disposed thereabove to facilitate the free swinging movement of the levers on the pins 42'. The levers 40 and 40a have complementary inner ends which are disposed outwardly with respect to. nearly diametrically opposite portions of the periphery "of the wheel 34.

Blocks 46 and .4 6a'fare secured in'inner'adjacent' sides of saidrinner ends of the levers 40' and 40a, respectively,

7 and are disposed longitudinally thereof. The blocks 46" and 46a have inner-.1 adjacent faces, facing toward the; periphery of the wheel 34 and which are providedwith transversely extending teeth 47 and 47a, respectively, sized for intermeshing engagement with the teeth The opposite'ends of the levers and 40a extend from the z pivots 42 toward and'to' adjacent thefront; edge. 21 of the table top 11* and are p rovided with restricted termik another and accordingly urge the inner ends oi said levers and the blocks; or racks 46rand 46a to swing toward 'one' another and toward the toothed periphery of the wheel'34.

' A hanger 51'is secured to the underside of 'the outer, V tabletop section 13 by fastenings'52 and isfldisposedfwith another side thereof preferablyfl'ush' with the front edge" 50 headedpin 53, as best seen in Figure, 5; extends out-' :Wardlyrthr'ough and is journalled in'saidhanger member 51'and into a central 'socket 5 4 which opens outwardly of an inner side of an actuating block 55; which inner side bears'turnably'against the outer side of the hanger 1 member 51; The block 55 is' secured to the pin5 3iby-a ,setsci'w 56 which is thre aded into sa id block atsub- ,s tantially -a right angle to the axis of the pin 53' and which s has arlriin'ner' end seating'in; ,a, radially openingfrecess 57 of the pin ;53-to thus'detachably secure theblock 55 to said pin. The hanger, -51 is provided with arcuate V slots 58fdisposed above and beneaththepin SS;};Pins 59..

ex'tend'loos'ely thronghsaid slots 58 and ihavethre'adegl 1 end's'60 which are anchored'in the block, 55; 'The'opposit'e i ends of'the pins'59 proiecttrom the'inner side ,oitheghanga er-251T loosely through longitudinally elongated .slots' filj in adjacent ends of a pair of links 62 and 62a. 'ThelinksfiZ and'62ar extend in oppositegdirections fromthe'hanger fl afid'haveremote ehdS'Which engage over and arepivotally 21 and interr'nedia'te of the ends of the table top '11: A

oonne'cted to thQej terminals 148 of the levers "40 and 740a,

V respectively; A handle 63 'is'fsecured' to and projects outwardly from a portion of .th V peripheryloffflle actu surface 'of theouter table sectio'n B,

markings and graduations 64; The upper surface of the which designates the'center of said turntable and is provided near its periphery with outwardly directed arrows 5 66 disposed in alignment with therarms of the cross 65; a 7 and which are thus spaced 90 degrees apart. A conven V r tional T-square is adaptedito; beiusedwith the drafting f the front edge 21 of the tablefltop. 7 r

As illustrated in'FigUijE'IZ, the'bloclts or racks'46 and are spaced frontithe' pivotsrltof their'levers slightly different distances: Thusgwhen the-teeth 47q'arc'n1eshor example, to a position at a degree angle to its' initial position, the'dra ftsman'or artisttgr'asps the handle moved'to actuate the lever 49a to swingsaidleverclock 'wase as seen iii/Figure Z tQ diseng'age its rack 46n'trorn' movement of'the link 62:; andleyer' 40a,the link '62 and will be rockdsimultaneously for swinging' theirfinner racks 46'and 46aheld disengaged, Qthe turntable"l2jrna"y be manually turned with the supporting plater27, sha'ft Q, a 31 and wheel 34.: Assuming that the turntable is turned j through. an arc of 45rdegrees'ina eounterclockwisedirec r; 1 'tion asseen in Figurerl"to positionrthe uppennost arrow of Figure l inradial alignment withthe 45 degree 3' graduation 64, when this has been accomplished pre'ssure', t V s on the handle 63 is released Thesprings will th'n, urge the outer endsof the levers 40' and 40a to swing" away from one another for'turning the block ;-in' the ,5 opposite'direction or clockwise as seenrin Figure 6; due I to a pull being exerted onthe pins 59 'byQthelinks-j62fj and 62a. However, as the rack teeth 47a;mesh withthe.

"teeth 35 in the even degree positionsof the'turntableli 1 vand as the turntable 12 .is' nowza 45"deg1 eef'or odd-degree j position,- the teetl1i47 will assume meshing-engagement" with the:teeth.35 while theateeth,,;47a will restagainstfl. I the outer ends of the teeth 35 and out or meshtherewith'. i 7 Thus, the upper 'pin 59 willithen be in engagement within, the outer end .of theslot'61 of the link 62while the lowery;

pin 59 willengage the inner; endofitheslot 61 ofith'e link 62a. It will thus, be se en that thexturntablefnri'aybe readily'locked in any one of 360 ,difierentequally spaced? 7 1 positions of rotation. s

turntable :12 'is provided withua cross the center of ,7 table 10- The ead 8 .otifl e q e 7 be r inst 7 an endioftheouter;section13 so'that the bar 69qof,the

T-squareextends across theturntable 12 and pa'ralleLto V z the wheel teeth 35 the teeth 4! will be out i s 12 in anyone of 360gequally spaced diifererit'posif 63' and'by turning said handleanti the block 55 clock- :wise as seen in Figure 3,'will c'anse the pins 5910 turn; 7 with the block 55 in the same direction/tor connterclock wise as seen in Figure 6 Duringftheinitialmovernerit oi thebloc'k 5S and pins '59, the link 620 will be initially! meshing engagement withthe wheeliteethfii due toithe" j factthat the lower" pin 59 is engaging thei ouf er fendof f v the slot 61 of said link'62a, 'How'ever, during'thi'sjnitial lever 4tl'will not be actuated since as seen-in Figure '6,- the upper'pin 59'is- 'engagingthe inner; end 'of the slot 7 p 61 of the link-'62 andj'will 'therefore' 'rnoveinitially towardtheouter end or said slot 61.:By the time that the teeth 47a are .disengag'edfromtheteeth 35, the upper pin 59 will be in engagement with the outer end of the, t 7 slot 61 of link 62, afterwhichb'otli levers 40 fanclffla I r Thus the need for angles isreliminated'since the draw ing paper may be positioned at'any desired, awes me lines may be drawn thereon at any:de'siredfangle'with the l use of the T-square67.; Obviously, th'turntablefc'an beg very rconvenien'tlyr employed by a dratts'manrorrartist in lettering onian sar'c as the paper canlbe turned-with .:the

turntable without lifting it or moving it relatively thereto and with the assurance that the paper can be returned with the turntable to its exact original position. Numerous other advantages of the structure will also be apparent to artists and draftsmen. As for example, in making perspective drawings an imaginary diminishing point can be established and with the use of the T-square and by slightly turning the turntable and paper a perspective drawing can be accurately produced.

The links 62 and 62a may be detachably connected in any suitable manner to the lever ends 48 and pins 59. For example, cotter pins 70 may extend through the lever ends 48 outwardly of the links, and the outer exposed ends of the pins 59 may be provided with grooves 71 for receiving spring split rings 72, as seen in Figure 8, for retaining the links in engagement with said pins.

Various modifications and changes are contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter defined by the appended claims.

I claim as my invention:

1. An apparatus of the character described comprising a wheel having a toothed periphery, a shaft extending centrally through and fixed to said wheel, a supporting structure in which the shaft is journaled, manually actuated means including a part pivotally mounted on the supporting structure and having a rack swingably movable into and out of meshing engagement with the wheel teeth for locking the wheel in dilferent rotatably adjusted positions relative to said supporting structure, said manually actuated means including a second part pivotally mounted on said supporting structure and having a second rack swingably movable into and out of meshing engagement with said wheel teeth, said racks being spaced different distances from the pivots of said parts whereby when either rack is in engagement with the wheel teeth the outer ends of the teeth of the other rack will be in abutting engagement with the outer ends of the wheel teeth whereby said wheel may be locked by said manually actuated means in twice as many different positions of rotation as the number of teeth provided on said wheel, said parts of the manually actuated means comprising levers, said racks being secured to complementary ends of said levers, said pivots being spaced from the ends of the levers, a hanger secured to and depending from a part of said supporting structure, a manually turnable part journaled on said hanger, links having corresponding ends pivotally connected to the opposite ends of said levers, and means pivotally connecting the opposite ends of said links to said manually turnable part on opposite sides of the journal thereof and constructed and arranged whereby rotation of said manually turnable part in one direction will initially cause one of said links to exert a pulling force on the lever the rack of which is in mesh with the wheel teeth to disengage said rack from meshing engagement with the wheel teeth and will subsequently cause both links to exert pulling forces simultaneously on both levers for swinging the racks simultaneously away from said toothed wheel.

2. An apparatus as in claim 1, said means connecting the manually turnable part to said links including pins, said links having longitudinally elongated slots forming a part of said means and engaging said pins, said slots permitting limited movement of the pins relative to the links, said slots having outer ends engaged by the pins for exerting pulling forces on the links, the link, connected to the lever the teeth of the rack of which is in abutting engagement with the outer ends of the wheel teeth, having the outer end of the slot thereof spaced from the pin which engages said slot when a pulling force is initially exerted on the other link, and spring means connecting the levers to said supporting structure and urging the levers to swing in a direction for moving the racks toward the toothed wheel.

References Cited in the file of this patent UNITED STATES PATENTS 173,410 Longin Feb. 15, 1876 350,469 Scott Oct. 5, 1886 398,906 Silvey Mar. 5, 1889 604,766 Korell May 31, 1898 646,287 Hundhausen Mar. 27, 1900 824,966 Werner July 3, 1906 1,169,239 Coder Jan. 25, 1916 1,200,822 Erickson Oct. 10, 1916 1,344,900 Juresisin June 29, 1920 1,440,993 Hasbrouck et al. Jan. 2, 1923 1,623,026 Cabezola Mar. 29, 1927 1,740,831 Patterson Dec. 24, 1929 2,154,460 Lawrence Apr. 18, 1939 2,317,042 Evans Apr. 20, 1943 2,399,906 Bentley May 7, 1946 2,511,349 Klay June 13, 1950 2,538,022 Lynxuiler Jan. 16, 1951 2,635,481 Orlow Apr. 21, 1953 FOREIGN PATENTS 1,059,921 France Nov. 18, 1953 

